|integer||The index of the shader sampler to assign source to|
|sprite/string||The source sprite or surface to assign to sampler (string required for surface)|
|real||The source image index, if source is a sprite|
Checks whether the source sprite or surface exists, and if so, assigns it as a sampler to the current shader
As this script is run automatically by VNgen draw functions, it is almost never necessary to run
See Shaders for a list of included shaders.